kmp in java

kmp.java

package Notepad;

public class KMP {
  
	static int[] getNext(String p){
		int i=1,j=0;
		int[] next = new int[p.length()+2];
		char[] pattern = p.toCharArray();
		
		next[0] = -1;
		next[1] = 0;
		
		while(i<p.length()-1){
			if(pattern[i] == pattern[j]){
				i++;
				j++;
				next[i] = next[j];
			}
			else if(j == 0){
				next[i+1] = 0;
				i++;
			}
			else{
				j = next[j];
			}
		}
		
		return next;
	}
	
	static int findKMPSub(String str, String p,int start, int next[]){
		char[] string = str.toCharArray();
		char[] pattern = p.toCharArray();
		int i = start;
		int j=0,v;
		while(i<str.length() && j<p.length()){
			if(j == -1 || string[i] == pattern[j]){
				i++;
				j++;
			}
			else{
				j = next[j];
			}
		}
		if ( j == p.length()){
			v = i - p.length();
		}else{
			v = -1;
		}
		return v;
	}
	
	static int findSub(String str, String p, int start){
		int m = p.length();
		int[] next = new int[m];
		next = getNext(p);
		int v = findKMPSub(str,p,start,next);
		return v;
	}
	

}